( function () {
/**
 * NURBS surface object
 *
 * Implementation is based on (x, y [, z=0 [, w=1]]) control points with w=weight.
 **/

class NURBSSurface {
  constructor(degree1, degree2, knots1, knots2
  /* arrays of reals */
  , controlPoints
  /* array^2 of Vector(2|3|4) */
  ) {
    this.degree1 = degree1;
    this.degree2 = degree2;
    this.knots1 = knots1;
    this.knots2 = knots2;
    this.controlPoints = [];
    const len1 = knots1.length - degree1 - 1;
    const len2 = knots2.length - degree2 - 1; // ensure THREE.Vector4 for control points

    for (let i = 0; i < len1; ++i) {
      this.controlPoints[i] = [];

      for (let j = 0; j < len2; ++j) {
        const point = controlPoints[i][j];
        this.controlPoints[i][j] = new THREE.Vector4(point.x, point.y, point.z, point.w);
      }
    }
  }

  getPoint(t1, t2, target) {
    const u = this.knots1[0] + t1 * (this.knots1[this.knots1.length - 1] - this.knots1[0]); // linear mapping t1->u

    const v = this.knots2[0] + t2 * (this.knots2[this.knots2.length - 1] - this.knots2[0]); // linear mapping t2->u

    THREE.NURBSUtils.calcSurfacePoint(this.degree1, this.degree2, this.knots1, this.knots2, this.controlPoints, u, v, target);
  }

}

THREE.NURBSSurface = NURBSSurface;
} )();
